1. Technical Field
This invention relates generally to mass mail handling equipment. More particularly, this invention relates to an improved apparatus for taking a series of flat articles such as envelopes, orienting them, and then stacking the articles in groupings.
2. Description of Related Art
In the high volume mail industry, in both U.S. First Class and Third Class mail, envelopes are filled with various letter pieces using automated mail inserters. For example, U.S. Pat. No. 5,029,832 and U.S. Pat. No. 5,211,384 disclose an in-line inserter device having envelope and feeding assemblies, an envelope inserting station, a sealing and stacking assembly, and various diverter stations.
Mass-mailing equipment has become very diverse in its functions. For instance, inserting equipment transport envelopes along an inserting track while various types of inserts are automatically inserted into the envelopes. The envelopes are normally transported to another piece of equipment that automatically seals the envelopes, weighs them and affixes postage. Still additional equipment automatically reads the zip codes or zip code indicia on the envelopes and indicates zip code breaks in the envelope groups or zip code pre sorting. This allows the user to take advantage of lower postage rates. Other mass-mailing equipment may include remittance processing equipment and zip code sorting equipment.
Customers utilizing mass-mailing equipment may have differing needs and requirements. Therefore, mass-mailing equipment is generally designed for one specific function. Each piece can then be connected by conveyor or other transport means to additional mail processing equipment so that a customized system can be assembled. One problem with this approach is that adjacent mail processing equipment may require the envelopes to be oriented in a position which is different from the discharge device of the preceding equipment. This necessitates transition conveyors or re-orientation devices.
For example, most mail processing inserting equipment in use today move the envelopes along a track with their faces (the addresses) face down and the flaps extended with the back of the flaps up during the insertion mode. The envelopes, as they leave the inserting machine, may have the flaps moistened and sealed before exiting the inserting machine. If the envelope is then going to have postage applied, it must be turned over 180 degrees so that the postage can be affixed to the face of the envelope. Other operations may require the envelope to be turned 90 degrees.
Currently, many inserters simply eject the filled envelope onto a short flat conveyor, allowing the envelopes to free float on the conveyor. This causes the possibility that the zip order of the envelopes will get mixed up, the possibility of envelopes becoming disorderly and difficult to quickly pick up, and the possibility of envelope flaps popping open prior to proper glue drying. Additionally, this method is an inefficient use of conveyor space, allowing only a short amount of time before the conveyor becomes full. This requires the increased attention from an operator. Often, an operator is forced to shut down the entire machine to catch up with the emptying of the conveyor. Obviously, doing so drastically reduces the overall throughput of envelopes.
These mail inserters may run at high speeds, up to thousands of envelopes per hour. Such speeds have created a need on the end of the inserters to collect the filled envelopes in such a way as to allow the operator to load them into mail trays or other forms of storage quickly and efficiently.
This area has proven to be a bottleneck of the mail insertion process. Many times, the operator has a difficult time keeping up with the inserter. To address the bottleneck, an envelope stacking apparatus is sometimes provided at the end of the system to secure the sorted mail pieces in a stacked position, facilitating the orderly removal of the processed mail pieces from the system.
One such stacking apparatus is disclosed in U.S. Pat. No. 4,705,157. Here, a device is disclosed for turning envelopes 90 degrees as the envelopes are moved forward through the device from an entrance location to an exit location using two endless belts adjacent to one another. The envelopes are ultimately stacked once they leave the exit location.
U.S. Pat. No. 6,398,204 provides an on-edge stacking apparatus that accepts envelopes in a flat condition, reorients them 90 degrees to an on-edge position, and stacks them in a tray, keeping the envelopes in order. The on-edge stacking apparatus provided by this patent is a tolerable solution in cases where the envelopes to be stacked are always of the same size. But in cases where the envelope size changes, an operator must reposition the on-edge stacking apparatus relative to the envelope feed tray (which is attached not to the stacking apparatus but to upstream equipment) because the envelopes are fed to the stacking apparatus from the feed tray top-edge justified to a register (backstop) of the feed tray, and so without repositioning, when larger envelopes arrive at the feed tray and are then rotated inside the stacking apparatus before being stacked on-edge in the output tray, the bottom of the larger envelopes protrudes down below the floor of the output tray. A solution to this problem is to interpose a bottom-edge aligner so that envelopes are input to the stacking apparatus bottom-edge aligned/justified, but such equipment can be expensive and consumes space, very often a scarce resource.
What is needed is an on-edge stacking apparatus that requires neither an interposed bottom-edge aligner, or having an operator manually adjust the position of the stacking apparatus relative to the input/feed tray to compensate for different sized envelopes.
Accordingly, in a first aspect of the invention, a stacking apparatus is provided, comprising: a belt-turn up mechanism having an entry nip and an egress nip, for receiving a plurality of articles arriving successively at the entry nip in a flat orientation, for rotating the articles from flat to on-edge, and for providing the articles successively on edge at the egress nip; and a discharge magazine, disposed adjacent the egress nip, for receiving successively each article provided on edge, and for stacking the articles on edge; wherein the belt turn-up mechanism comprises means for pivoting the egress nip substantially about the entry nip, thereby allowing adjustment of the stacking apparatus for different sized articles.
In accord with the first aspect of the invention, the belt turn-up mechanism may include two belts and four pulleys, of which two pulleys form the entry nip and two pulleys form the egress nip.
Also in accord with the first aspect of the invention, the means for pivoting the egress nip substantially about the entry nip may be a screw adjustment.
Still also in accord with the first aspect of the invention, the stacking apparatus may also include: a sensor for sensing the size of a next article at the entry nip and for providing a sizing signal conveying information about the size of the next article; a controller, responsive to the sizing signal, for providing an adjusting signal based on the sizing signal; and a motor, responsive to the adjusting signal, for providing a force for pivoting the egress nip substantially about the entry nip.
In a second aspect of the invention, a method of operation of a stacking apparatus, comprising: a step of receiving a plurality of articles arriving successively at an entry nip in a flat orientation, rotating the articles from flat to on-edge, and providing the articles successively on edge at an egress nip; a step of receiving successively each article provided on edge, and for ejecting the articles at an egress nip so as to stack the articles on edge; and a step of pivoting the egress nip substantially about the entry nip as needed to allow adjust for different sized articles.